Over the years, digital video content has gained increasing popularity with consumers. With the increasing amount of audio and video content available to consumers through broadcast, cable, on-demand, fixed media, and other available sources of multimedia content, consumers have easy access to an increasing amount of content and programming. Furthermore, many devices (e.g., PCs, DVD recorders) and services that are readily available allow consumers to record, time-shift or view on-demand video and audio content. Furthermore, an increasing amount of video content is becoming available over the Internet and other data services in the form of downloadable content such as IPTV (Internet Protocol Television) delivered video services.
Generally, video content can be stored in any number of common formats such as MPEG-1, MPEG-2, or DV (digital video), for example. Likewise, audio content may be stored in any number of common digital formats such as MP3, WAV, or MPEG Audio, for example. The availability of multimedia content in a vast array of digital formats has helped make distribution of multimedia content easier because of the high degree of portability.
Video playback systems are well known, and there are a variety of current standards that govern the format and other attributes associated with the various video playback systems. Today, the DVD (Digital Video Disc) standard is the predominant format utilized for optical disc storage because of its high storage capacity, thus enabling high quality video and audio to be stored. Consequently, media content such as movies, television shows, and music videos are made widely available in DVD format.
Currently, there are various standards in consideration to become the successor to the DVD standard. Two formats competing to become the next generation optical standard are Blu-ray Disc and HD DVD (High Definition Digital Video Disc). As with other newer standards, Blu-ray Disc offers advantages over DVDs and other previous optical standards in various ways including increased storage capacity and enhanced interactivity (disc content authoring, seamless menu navigation, network/Internet connectivity, etc.). The Blu-ray Disc framework offers content providers almost unlimited functionality when creating interactive titles. The author has complete freedom in designing the user interface, which is controllable by using standard navigational buttons on a remote control. These newer-generation video standards such as Blu-ray Disc and HD DVD are providing greater levels of user control and interactivity with the underlying video content.
Unfortunately, piracy of audio/visual works has also proliferated over the years as technology continues to facilitate the distribution of multimedia content. Because of the capability in accessing and copying multimedia content stored on DVDs, for example, video and audio piracy continues to be an ongoing problem. Such piracy continues to be a problem even in light of the copy-restricted mechanisms that DVDs generally employ. Furthermore, with the newer standards such as HD DVD and Blu-ray Disc that offer increased interactive features, video and audio piracy will likely be an ongoing problem.
In response to unauthorized copying and distribution of multimedia content, publishers and authors of audio/visual works have relied on technologies that control access to digital content. The term Digital Rights Management (DRM) generally describes technologies used to achieve restricted access to multimedia content. Such DRM technologies are based on a large variety of technologies, including multimedia player software that control access to content using encryption. However, one apparent shortcoming of using software applications to control access to encrypted content is that such software can be accessed and reversed-engineered in many cases. Even with the existence of protection mechanisms on DVDs, users have discovered ways to circumvent these protection mechanisms. One way is by modifying commercial DVD playback software whereby decrypted and decoded multimedia streams are written directly to the hard disk on a computer.
Given that personal computers generally operate in an open environment, it can be a challenge to protect such applications as DVD playback software. In some instances, software code can be dissected and analyzed, thereby exposing sensitive data embedded within the program. This can prove to be very costly as such data as decryption keys used for distributing content incorporating DRM may be obtained and reused. With the proper tools, it is possible to examine blocks of memory holding these keys to gain unauthorized access to protected content. Thus, conventional approaches involving software applications stored in open memory suffer from various apparent shortcomings.